1. Field of the Invention
This invention relates primarily to the waterjet field and more specifically to providing a method to direct a stream of water or fluid to steer the waterjet vessel in such a manner that minimal power losses occur as a result of the redirection of the stream of water or fluid from the waterjet.
2. Description of the Prior Art
There are many patents in the prior art that are directed to a means to deflect a stream of water from a waterjet to provide thrust vectoring either in the horizontal or vertical plane. All of the prior art patents known to the Applicant deflect a solid stream of water from a waterjet pump after the stream has already reached its peak velocity, thus any interference with the stream of water will reduce the overall thrust efficiency through friction losses. For example, U.S. Pat. No. 3,143,857 describes a waterjet device wherein the water is accelerated through an axial flow-type of pump. The pump discharges into a separate jet nozzle which is pivotable about a spherical housing in a horizontal plane. Additionally there is a reversing bucket associated with the pivotal housing to direct the water discharged into the nozzle housing in an opposite direction. Friction losses are incurred when the water being accelerated through the pump are directed into a separate nozzle. The more the steering nozzle is deflected, the greater the friction losses. Obviously, power is lost through increased friction in the transition distance between the internal fixed nozzle and the deflected separate external nozzle associated with the spherical housing. An obvious disadvantage then, is the separate swivel nozzle that deflects a solid stream of water from a fixed pump and deflects the stream to steer the waterjet.
U.S. Pat. No. 2,993,463 describes a waterjet having a pair of alternating nozzles, one or the other of which communicates with an outlet opening from a waterjet pump. One of the nozzles being directed 180.degree. to the direction of the other to provide for a reverse function for a watercraft. This device, like the foregoing patent, is disadvantaged in that the water accelerated through the pump is redirected after it passes through a primary opening, thus frictional losses similar to that which occurs in a pipe elbow are incurred with increased deflection of the secondary nozzles.
The patents described above are but examples of many similar patents in the prior art. All of the prior art water propulsion devices deflect a primary stream of water from a pump or the like to effect steering, reversing etc. The more the angular deflection of the nozzle, the greater the propulsion losses are incurred thereby diminishing the propulsion efficiency. The present invention overcomes this serious problem by vectoring fluid or water upstream of the nozzle where full velocity is achieved. The accelerated water is directed through a specific horizontal or vertical plane without serious frictional losses.